1. Field of the Invention
The present invention relates to a liquid crystal display module, and more particularly to a liquid crystal display module which is capable of indicating, in cooperation with an indicating unit to be connected to the module, whether signal terminals of a heat seal are precisely aligned with signal terminals of a circuit substrate or not, prior to a heating press treatment in a bonding process of the module, and thereby allowing the module to be precisely bonded and reducing the time for the bonding process of the module.
2. Description of the Related Art
A conventional liquid crystal display module generally includes, as illustrated in FIG. 1, a circuit substrate 10 which is provided with a circuit pattern having signal terminals adapted to receive a liquid crystal drive signal outputted from an external device, a liquid crystal display unit 30 which is fixedly mounted on the circuit substrate 10 and adapted to achieve a display according to the liquid crystal drive signal, and a heat seal 20 for connecting the signal terminals of the circuit substrate 10 to the signal terminals of the liquid crystal display unit 30, respectively.
As shown in FIG. 2, the circuit substrate 10 is provided at its upper surface (the right side surface in the drawing) with a plurality (for example, four) of cross-shaped positioning marks 11 and with a plurality of signal terminals 12 that are provided by a circuit pattern made of a conductive material. Similarly, the heat seal 20 is provided at its upper surface with a plurality of cross-shaped positioning marks 21 and with a plurality of signal terminals 22 that are provided by a circuit pattern made of a conductive material. Also, the liquid crystal display unit 30 is provided at its upper surface with a plurality of cross-shaped positioning marks 31 and with a plurality of signal terminals 32 that are provided by a circuit pattern made of a conductive material. Cross-shaped positioning marks 11, 21 and 31 of the circuit substrate 10, the heat seal 20 and the liquid crystal display unit 30 correspond to one another, respectively, and are adapted to be aligned with one another for precisely aligning the circuit substrate 10, the heat seal 20 and the liquid crystal display unit 30 with one another when bonding them together. Also, signal terminals 12, 22 and 32 of the circuit substrate 10, the heat seal 20 and the liquid crystal display unit 30 correspond to one another, respectively.
In particular, the heat seal 20 includes a resin substrate 25 having a pattern which provides the cross-shaped positioning marks 21 and the signal terminals 22, as shown in FIG. 4. The cross-shaped positioning marks 21 and the signal terminals 22 are covered with an anisotropy conductive material 24. An insulation material layer 23 is deposited on the anisotropy conductive material layer 24.
In bonding, the worker aligns manually the circuit substrate 10, the heat seat 20 and the liquid crystal display unit 30 with one another while determining by a magnifying glass whether corresponding positioning marks 11, 21 and 31 of the circuit substrate 10, the heat seal 20 and the liquid crystal display unit 30 are precisely aligned with one another. Under this condition, the relative positions of the circuit substrate 10, the heat seal 20 and the liquid crystal display unit 30 are fixed by using a soldering iron. Thereafter, the circuit substrate 10, the heat seal 20 and the liquid crystal display unit 30, which are firmly maintained in their precise relative positions, are heat pressed by a heat pressing machine so that the liquid crystal display unit 30 is bonded to the circuit substrate 10, via the heat seal 20, to form a liquid crystal display module.
However, the determination for the alignment of positioning marks by the use of a magnifying glass and the manual fixing by the use of a soldering iron, which are required in bonding the above-mentioned construction of the conventional liquid crystal display module, is an unscientific and troublesome method. As a result, the alignment of positioning marks may be frequently incorrect, and thereby the rate of poor products increases. This also leads to the waste of materials. Furthermore, the productivity is reduced since the procedure for aligning the positioning marks is manually carried out by the determination through a magnifying glass.